Can't open camera first time about mobilevisionbarcodescanner HOT 6 CLOSED

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/root_blur_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <include
        android:id="@+id/mainLayout"
        layout="@layout/toolbar" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/mainLayout"
        android:background="#000"
        android:gravity="center"
        android:orientation="vertical"
        android:paddingTop="50dp">

        <LinearLayout
            android:id="@+id/cam_layout"
            android:layout_width="300dp"
            android:layout_height="300dp"
            android:orientation="vertical"/>


        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:padding="16dp"
            android:text="Align the QR Code/bar code within the frame to scan"
            android:textColor="#fff" />

    </LinearLayout>

</RelativeLayout>

View camView = LayoutInflater.from(this).inflate(R.layout.cam_layout, null, false);
                ((LinearLayout) findViewById(R.id.cam_layout)).addView(camView);
                barcodeCapture = (BarcodeCapture) getSupportFragmentManager().findFragmentById(R.id.barcode);
                barcodeCapture.setRetrieval(this);

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/barcode"
    android:name="com.google.android.gms.samples.vision.barcodereader.BarcodeCapture"
    android:layout_width="300dp"
    android:layout_height="300dp"
    app:gvb_auto_focus="true"
    app:gvb_code_format="all_format"
    app:gvb_flash="false" />